Apparatus for molding sponge rubber



Nov. 14, 1939. H. R, MINQR APPARATUS FOR MOLDING SPONGE RUBBER 2 sheets-sheet 1` Filed Deo. 1

Nov. 14, 1939. H. R. MINOR 2,180,304

APPXRATUS` FOR MOI DIG SPONGE RUBBER Filed Dec. 1, 1937 2 Sheets-Sheet 2 SOFT SPONGE RusER STIFF SPONGE R UBBER SOFT SPONGE RUBBER STIFF SPONG'E RUBBER INVENTOI? HENRY R. MINOR- A Tron/v5 Ys Patented Nov. 14, 1939 2,180,304

Unire srmss AT ENT, orties APPARATUS FOR MOLDING SPGNGE .RUBBER Henry E. Minor, Dayton, Ohio, assignor to Inv dustrial Process C'orp., Dayton, Ohio, a corporation of New York apprises@ December 1, 1937, serial No. 177,649 s claims. (c1. is-ao This invention relates to apparatus for molding and also preferably have the ends i2 oi' the pasrubber articles, andinparticular, to apparatus for sageways H open to the atmosphere. The admolding sponge rubber articles. vantage of this construction is that when a heavy `One object of this invention is to provide a body depresses the cushion, as at i3, the sponge molding apparatus for producing sponge rubber -rubber portion of the cushion not only will yield 5 articles having elongated cavities or apertures Vin its usual manner, but the passageways ll will therein. become distorted or flattened and expel some of Another object is to provide a molding appathe air therefrom, and increase the resilience of ratus for molding sponge rubber articles, wherethe cushion. The cushion of Figures land 2 is l0. in means is provided for supporting successive not necessarily homogeneous, but may have diflayers of sponge rubber batch in spaced positions ferent characteristics in diierent layers, as hereso that when the assembly is heated the batch inaiter set forth in more detail. The outer porlayers will soften and expand around the supports tions, for example, may have different densities to forma sponge rubber body with elongated aperor porosities than the inner portions. In this l5- tures therein. manner the surface portions of the cushion lil 15A Another. object is to provide a molding appamay be given characteristics for improving the ratus for molding sponge rubber articles consistappearance of the article, as well as for providing ing in a mold having removable supports for supa suitable surface for the application of tradeporting a plurality of rods or pipes upon which marks, identifying data or designs.

layers of rubber batch may be placed, whereupon A preferred apparatus for making the cushion 201 the heating of the assembly causes the layers of of Figures l and 2 is shown in Figure 3, and conrubber batch to expand and unite with one ansists of a-mOidng apparatus. generally designated other around the supports, thereby forming a 2c, having relatively thin side walls 2l, a bottom sponge rubber body with tubular apertures or paswall 22 and end walls 23 and 2t. The walls 2i 25 sageways therethrough after the supports are to 2/i,inclusive, are preierably'oic thin sheet metal, 25. removed from the apparatus. the provisiony of a top 25 being optional. The

In the drawings: showing of the molding apparatus 2o is diagram- Figure l is a side elevation of a sponge rubmatic in the several views. Arranged within the ber body, such as a cushion, produced in the moldmolding apparatus 3i! iS a partition 2@ having 2' ing apparatus of this invention. plurality of apertures 2i for the admission andl 30 FigureZisafront elevation, partly broken away, support ci rods or pipes 28.' For purposes of of the sponge rubber body shown in Figure 1. simpliiication only the top layer of rods or pipes Figure 3 is a perspective view of the molding is. shown within the apparatus 20, the mid-porapparatus of this invention, with the under layers tions thereof being broken off immediately after v or pipes removed to simplify the showing, but passing through the end wall 24. Similar aper- 35 with the ends of the removed pipes shown emergtures 29 are provided in the end wall 24. The ing from the side wall of the apparatus.y apertures 21 and 29 are slightly larger than the Figure 4 is -a cross sectional view of the aprods or tubes 28 so as to provide a loose, sliding paratus shown in Figure 3, with the sponge rubber l fit therebetween. Preferably also the end wall 23 40 batch layers in position at the start of the moldis provided with apertures 30 for the passage rof 40'1 ing operations. the outer endsof the rods or pipes 28.

Figure 5 is a view similar to Figure 4, but show- The end wall 2A is removable from the appaing the drooping of the sponge rubber batch ratus sothat the pipes 28 may be temporarily layers shortly after the commencement of the supported solely by the partition 25 cooperating molding operations. with the end wall 23. In this manner the suc- 45 Figure 6 is a View similar to Figures 4 and 5, cessive layers of sponge rubber batch may be conbut showing the appearance of the completed veniently inserted before the end wall 24 is placed sponge rubber article in the lmolding apparatus in position. The ends of the pipes 28 may be bevafter the molding operations have been' termieled, if desired, to `facilitatetheir admission to nated. f and passage through the various apertures 21, 29 50 Referring to the drawings in detail, Figure 1 and 30. The pipes 28 are preferably of metal with shows a sponge rubber cushion, generally desiga plated coating, tending to render them non-adnated i8, having a multiplicity of tubular pashesive to the rubber, such a plated coating as sageways i I therethrough. These tubular paschromium, cadmium or the like being found suitsageways are preferably parallel to one another able for this purpose. The pipes may optionally 55 the rubber batch layers to be placed in position,

one layer at a time, followed by a layer of pipes, then another layer of rubber batch, etc. until the molding apparatus 20 has been lled. This prevention of the marring or" the pipes keeps their surfaces in perfect condition, and facilitates the withdrawal of the pipes from the rubber article after the manufacturing process has been completed.'

In the method of making the rubber article shown in Figures 1 and 2, a layer 3| of suitable sponge rubber stock is placed upon the bottom 22 of the molding apparatus 20, with the end wall 2li thereof removed. The lowermost layer of the pipes 28 is then inserted, the pipes being Caused to pass through the apertures 2l and 3B, and thereby to be supported at one end. A

layer of pipes 28 is inserted in the same manner. 'I'his procedure is repeated until the desired number of alternate layers of pipes 28 and rubber batch layers 3l have been provided, The removable end 24 is then placed in position, with the ends of the pipes 28 passing through the apertures 29 therein. The top 25, if used, is then placed in position and the assembly placed in an autoclave and subjected to the usual processes of heating and expanding the rubber.

As the rubber is heated during the early part of the procedure, it droops and assumes the postion shown in Figure 5. The different batch layers 3| thus present, in cross section, an undulating appearance excepting, of course, bottom layer SI, which is supported by the bottom wall 22 of the molding apparatus 2). When the heating and expansion have been carried still further, the successive batch layers expand into engagement with one another, thereby lling the spaces between the pipes 28, and presenting the cross sectional appearance shown in Figure 6. By this method of using alternate layers of rubber batch and pipes, it is possible to obtain a sponge rubber article of any thickness desired, yet with a substantially constant density throughout, a problem which has hitherto presented great diiiiculties in the sponge rubber art. By varying the characteristics of the different layers 3 I it is also obviously possible to Vary the density or porosity of the resulting article I0. It is further possible to apply layers having different color characteristics, or different surface characteristics for the application of identifying data,

trade marks or designs. When the expansion and i cedure.

It will be understood that I desire to c'omprehend within my invention such modiiications as come Within the scope of the claims and the invention, f

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. In an apparatus for molding rubber articles comprising integral layers, a container having a removable wall, spaced apertures in said removable wall corresponding to spaced apertures in the wall opposite said removable Wall, horizontally disposed supports inserted in said apertures for supporting rubber stack layers in superimposed spaced relationship, an additional member arranged between said apertured walls, and means on said additional member for holding said supports in spaced positions during the removal of said removable wall.

2. In an apparatus for molding rubber articles, a frame having a pair of spaced supportholding members, elongated horizontally disposed supports for supporting layers of rubber stock, an additional support-holding member arranged intermediate said previously mentioned supportholding members, and means on said supportretaining members for removably holding said supports in spaced positions during the removal of one of said pair of spaced support holding members.

3. In an apparatus for molding rubber articles, a frame having a pair of spaced supportholding members, elongated supports retained by said spaced members for supporting layers of rubber stock in a horizontal position, an additional support-holding member arranged intermediate said previously mentioned support-holding members, and. means on said support-holding members for removably holding said supports, one of said support-holding members being removable whereby to permit said intermediate supportholding member and the other member to maintain said supports in their spaced positions to facilitate the insertion of rubber stock layers on said supports.

HENRY R. MINOR. 

